Whats the definition of an atoll?
atoll • \AT-tawl\ • noun. : a coral island consisting of a reef surrounding a lagoon.
What are atolls give example?
The definition of an atoll is a ring shaped coral reef, or close coral islands that enclose or almost enclose a lagoon. The Bikini in the Pacific Ocean is an example of an atoll. An island or chain of islets connected by a coral reef that nearly or entirely encloses a lagoon.
Why is it called an atoll?
The term “atoll” is derived from a Maldivian (divehi) word, atolu. Atolls are ring-shaped reefs that occur in mid-ocean, often in linear island chains or archipelagoes. The most extensive groups of atolls occur in the Pacific Ocean but there are also numerous atolls in the central Indian Ocean (Figure 1).
What is an atoll vs island?
As the reef expands, the interior island usually begins to subside and the fringing reef turns into a barrier reef. When the island completely subsides beneath the water leaving a ring of growing coral with an open lagoon in its center, it is called an atoll.
Why do atolls form?
The formation of an atoll is a slow process that can take millions of years. It begins when an underwater volcano erupts, creating a buildup of lava on the seafloor. With continued eruptions, the lava continues to build until it breaks through the ocean’s surface and forms an island.
Where is the world’s largest atoll?
Atolls are only found in the tropical and subtropical warm waters of the oceans and seas. Most of the world’s great atolls are located in the Pacific Ocean, especially in the islands of Tuamotu, Caroline, Marshall, and the Coral Sea.
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The Largest Atolls In The World.
| Rank | 1 |
|---|---|
| Name | Great Chagos Bank |
| Location | Indian Ocean |
| Area (km²) | 12,642 |
Where are atolls found?
Most of the world’s atolls are in the Pacific Ocean (with concentrations in the Caroline Islands, the Coral Sea Islands, the Marshall Islands, the Tuamotu Islands, Kiribati, Tokelau, and Tuvalu) and the Indian Ocean (the Chagos Archipelago, Lakshadweep, the atolls of the Maldives, and the Outer Islands of Seychelles).
What is a atoll in the ocean?
An atoll is a ring-shaped coral reef that forms as an old volcano erodes.
Which country has the most atolls?
The tiny country of the Maldives in the middle of the Indian Ocean is made up of about 1,200 tiny coral islands grouped into 26 atolls. The word atoll actually comes from the the Dhivehi (a language spoken on the Maldives) word “atholhu”.
Can people live on an atoll?
Atolls are often uninhabited “desert” islands. (Desert does not refer to the islands’ climate, but their “deserted” or uninhabited status.) Many are remote and difficult to reach.
What is the name of a famous atoll?
Kiritimati Atoll, also called Christmas Atoll, coral island in the Northern Line Islands, part of Kiribati, in the west-central Pacific Ocean. It is the largest island of purely coral formation in the world, having a circumference of about 100 miles (160 km).
Where is the world’s biggest atoll?
Most of the Great Chagos Bank is located underwater. An atoll is a ring-shaped coral reef or series of coral rims that encircle a lagoon either partially or wholly.
Do atolls float?
The first and most important fact, discovered by none other than Charles Darwin, is that coral atolls essentially “float” on the surface of the sea. Atolls exist in a delicate balance between new sand and coral rubble being added from the reef, and sand and rubble being eroded by wind and wave back into the sea.
Where is the largest atoll in the world?
Most of the world’s great atolls are located in the Pacific Ocean, especially in the islands of Tuamotu, Caroline, Marshall, and the Coral Sea.
How many atolls are there in the world?
440 atolls
There may be coral islands or cays on the rim. Atolls are located in warm tropical or subtropical oceans and seas where corals can grow. Most of the approximately 440 atolls in the world are in the Pacific Ocean.
Do people live in atolls?
Atolls are sparsely populated, low-lying islands whose white, sandy beaches and placid lagoons are ideally suited to the tourism industry. Island nations made of atolls include Maldives, in the Indian Ocean, and Kiribati, in the Pacific.
Do atolls have fresh water?
When precipitation recharge across an atoll island is sufficient, a fresh groundwater lens (FGL) will form, with freshwater floating above denser, saline groundwater derived from the sea. Rainfall and FGLs are the two main sources of freshwater for atoll island communities.
Where is the biggest atoll in the world?
How atoll is formed?
This circular type of coral reef, called an atoll, is created as a ring of coral surrounds an undersea volcano that has risen above the water’s surface. Long after the volcano has receded into the ocean, the atoll remains. The habitat inside the atoll, protected from the open sea by the sturdy reef, is called a lagoon.